Process for producing silver halide photographic light-sensitive material and product thereby

Abstract

A process for producing a silver halide photographic material and a photographic material produced thereby are disclosed. The process comprises the steps of (1) forming a seed emulsion comprising silver halide seed grains, (2) growing the seed grains to prepare a silver halide photographic emulsion by supplying a silver ion component and a halide ion component to the mother liquid of the seed emulsion, (3) coating and drying the photographic emulsion on a support to form the silver halide emulsion layer, and at least a period during the step for growing the seed grains is performed in the presence of silver iodide grains, and an oxidant capable of converting metallic silver to silver ions is added at a time during the step for growing the seed grains.

What is claimed is: 
     
       1. A process for forming a silver halide photographic light-sensitive material having a silver iodide-containing silver halide emulsion layer, said process comprising; forming a seed emulsion comprising silver halide seed grains,   growing said seed grains by simultaneously supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide, and a suspension of silver iodide grains, to a mother liquid of said seed emulsion to form a silver halide photographic emulsion, and   coating and drying said photographic emulsion on a support to form a silver halide emulsion layer,   wherein an oxidant capable of converting metallic silver to silver ions is added to said silver halide emulsion during the growth phase of said silver halide seed grains said oxidant comprising elemental iodine.   
     
     
       2. The process of claim 1, wherein said oxidant is added in an amount of from 10 -8  to 10 -1  moles per mol of silver halide. 
     
     
       3. The process of claim 2, wherein said oxidant is added in an amount of from 10 -7  moles to 10 -2  moles per mol of silver halide. 
     
     
       4. The process of claim 3, wherein said oxidant is added in an amount of from 10 -6  moles to 10 -2  moles per mol of silver halide. 
     
     
       5. The process of claim 1, wherein said seed grains mainly comprise monodispersed twin crystals. 
     
     
       6. The process of claim 5, wherein said monodispersed twin seed grains are formed by a process comprising the steps of forming nuclei grains under a condition that pBr value of the mother liquid of said seed grains is maintained at -0.7 to 2.0 during a starting period of exceeding 1/2 of a stage of precipitation of silver halide having a silver iodide content of 0 to 5 mol %, and   forming monodispersed spherical twin seed grains, following said nuclei forming step, in the presence of a silver halide solvent in an amount of 10 -5  moles to 2.0 moles per mol of silver halide.   
     
     
       7. The process of claim 1, wherein said silver iodide grains are a mixture of γ-AgI grains and β-AgI grains in which the number of γ-AgI is larger than that of β-AgI grains. 
     
     
       8. The process of claim 1, wherein said silver iodide grains have an average grain size of 0.001 μm to 0.7 μm. 
     
     
       9. The process of claim 8, wherein said silver iodide grains have an average grain size of 0.005 μm to 0.3 μm. 
     
     
       10. The process of claim 9, wherein said silver iodide grains have an average grain size of 0.01 μm to 0.1 μm. 
     
     
       11. The process of claim 1, wherein said halide compound solution contains no iodide ions. 
     
     
       12. The process of claim 1, wherein silver iodide grains exist over a period for forming a silver iodide phase of said photographic emulsion grains. 
     
     
       13. The process of claim 1, wherein said silver iodide grains are separately prepared in a vessel other than a reacting vessel in which said grain growing step is performed, and added to said mother liquid of seed grains. 
     
     
       14. A silver halide photographic light-sensitive material comprising a support having provided thereon a silver halide emulsion layer comprising silver halide grains containing silver iodide, said silver halide emulsion layer having been prepared by; forming a seed emulsion comprising silver halide seed grains,   growing said seen grains by simultaneously supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide, and a suspension of silver iodide grains, to a mother liquid of said seed emulsion to form a silver halide photographic emulsion, and   coating and drying said photographic emulsion on said support to form said silver halide emulsion layer,   wherein an oxidant capable of converting metallic silver to silver ions is added to said silver halide emulsion during the growth phase of said silver halide seed grains said oxidant comprising elemental iodine.   
     
     
       15. The light-sensitive material of claim 14, wherein said oxidant is added in an amount of from 10 -8  moles to 10 -1  moles per mol of silver halide. 
     
     
       16. The light-sensitive material of claim 15, wherein said oxidant is added in an amount of from 10 -7  moles to 10 -2  moles per mol of silver halide. 
     
     
       17. The light-sensitive material of claim 16, wherein said oxidant is added in an amount of from 10 -6  moles to 10 -2  moles per mol of silver halide. 
     
     
       18. The light-sensitive material of claim 14, wherein said seed grains mainly comprise monodispersed twin crystals. 
     
     
       19. The light-sensitive material of claim 18, wherein said monodispersed twin seed grains formed by a process comprising the steps of forming nuclei grains under a condition that pBr value of the mother liquid of said seed grains is maintained at -0.7 to 2.0 during a starting period of exceeding 1/2 of a stage of precipitation of silver halide having a silver iodide content of 0 to 5 mol %, and   forming monodispersed spherical twin seed grains, following said nuclei forming step, in the presence of a silver halide solvent in an amount of 10 -5  moles to 2.0 moles per mol of silver halide.   
     
     
       20. The light-sensitive material of claim 14, wherein said silver iodide grains are a mixture of γ-AgI grains and β-AgI grains in which the number of γ-AgI is larger than that of β-AgI grains. 
     
     
       21. The light-sensitive material of claim 14, wherein said silver iodide grains have an average grain size of 0.001 μm 0.7 μm. 
     
     
       22. The light-sensitive material of claim 21, wherein said silver iodide grains have an average grain size of 0.005 μm to 0.3 μm. 
     
     
       23. The light-sensitive material of claim 22, wherein said silver iodide grains have an average grain size of 0.01 μm to 0.1 μm. 
     
     
       24. The light-sensitive material of claim 14, wherein said halide compound solution contains no iodide ions. 
     
     
       25. The light-sensitive material of claim 14, wherein silver iodide grains exist over a period for forming a silver iodide phase of said photographic emulsion grains. 
     
     
       26. The light-sensitive material of claim 14, wherein said silver iodide grains are separately prepared in a vessel other than a reacting vessel in which said grain growing step is performed, and added to said mother liquid of seed grains.